Galactic Collisions Palen Full Test Bank - Understanding Our Universe 3e Complete Test Bank by Stacy Palen. DOCX document preview.
Mission 18: Galactic Collisions
MULTIPLE CHOICE
1. Which of the following galaxy types best describes the first galaxies to form in the Universe?
a. spiral d. flocculent
b. elliptical e. lenticular
c. irregular
2. For a galaxy with a redshift of z = 6, the radius of the observable Universe would have been what fraction of its current value?
a. 1/2 d. 1/7
b. 1/4 e. 1/12
c. 1/6
3. A burst of star formation in a galaxy is associated with all but which of the following?
a. a population of hot stars
b. enhanced supernova rate
c. infrared emission associated with hot dust
d. X-ray emission from superheated gas
e. low abundance of gas and dust
4. Which of the following most closely approximates the half-life of aluminum-26?
a. 70 yr d. 7,000,000 yr
b. 7,000 yr e. 7,000,000,000 yr
c. 700,000 yr
5. Supernova explosions play an important role in shaping the composition of galaxies and future generations of stars. Which of the following is not an element that requires supernova explosions to eject it into the galaxy?
a. mercury d. helium
b. copper e. oxygen
c. carbon
1. Hubble Space Telescope images of the most distant galaxies show them to be mostly irregularly shaped and often interacting with other nearby galaxies. Given that these galaxies are being observed early in the expansion and evolution of Universe, how do astronomers explain these observations?
2. Supernova explosions eject new elements out into space. The self-gravity of a galaxy holds onto this material, which eventually cools and finds its way into another generation of stars and planetary systems such as our own Solar System. It is believed that aluminum-26 was abundant in the early Solar System. What can be inferred from its abundance in the early Solar System?